Pros

Pro

No cloud

TagSpaces is running completely offline, sending no data to any cloud based service, unlike many Evernote alternatives.

Pro

No web service or database lock in

The backend is simply the directory and file structure on your harddrive.

Pro

Your can choose your cloud file storage

Using only files and no databases let's you make the decision with which cloud file sync service to use, making sure your notes are made available on other devices and platforms. It works great with Owncloud, Nextcloud, Dropbox or Google Drive.

Pro

Open source

TagSpaces is free and open source making it easily extendable with the help of extensions.

Cons

Con

It renames your files in order to tag them

The positive side of this drawback is that this way the tags are easily transferred to other platforms by simply syncing them.